title: An evaluation of BMP-2 delivery from scaffolds with miniaturized dental implants in a novel rat mandible model.
abstract: The purpose of this study was three-fold: (a) to develop a new small animal model to evaluate dental implant systems that recapitulates aspects of the challenging intraoral environment, (b) screen several scaffolds for in vivo bone forming efficacy when used to deliver non-glycosylated bone morphogenetic protein-2 (BMP-2) together with a miniaturized titanium (Ti) dental implant, and (c) identify correlations between in vitro BMP-2 release rates and in vivo results. The scaffolds tested were: (1) collagen-hydroxyapatite composite (Col/HA), (2) polyethylene glycol hydrogel (PEG-hydrogel), and (3) Col/HA infused with PEG-hydrogel (Col/HA/PEG-hydrogel). BMP-2 delivery directly from the Ti implants rather than from the scaffolds was also tested. MicroCT analyses at 4 weeks showed that the maximum volume and height of new bone occurred when BMP-2 (10 μg) was delivered from the Col/HA/PEG-hydrogel scaffolds. BMP-2 delivery from the Ti implant was not as effective as from the scaffolds. While in vitro BMP-2 release was highest for the PEG-hydrogel, the scaffold most successful in vivo was the Col/HA/PEG-hydrogel scaffold because it had the necessary mechanical strength to perform well in the mandibular bone environment. The in vitro release studies suggested a threshold dose of 5 μg which was borne out by the in vivo dose response studies.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Implant Dentistry, School of Stomatology, Nanjing University, Nanjing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wen
authors.forename: Matthias
authors.initials: M
authors.lastname: Karl
authors.forename: David
authors.initials: D
authors.lastname: Pendrys
authors.forename: David
authors.initials: D
authors.lastname: Shafer
authors.forename: Martin
authors.initials: M
authors.lastname: Freilich
authors.forename: Liisa
authors.initials: L
authors.lastname: Kuhn
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism* / Q000494:pharmacology; D003094:Collagen / Q000737:chemistry / Q000378:metabolism; D015921:Dental Implants; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry / Q000378:metabolism; D020007:Implants, Experimental; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000378:metabolism; D008422:Materials Testing; D023421:Models, Animal; D010012:Osteogenesis / Q000187:drug effects; D011092:Polyethylene Glycols / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D054457:Tissue Scaffolds / Q000737:chemistry*; D014025:Titanium
chemical_list: D001672:Biocompatible Materials; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D015921:Dental Implants; D004337:Drug Carriers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D003094:Collagen; D017886:Durapatite; D014025:Titanium